Frequently during use of microdispensers of the type disclosed in U.S. Pat. No. 3,815,790 for Precision Liquid Pipetting Devices issued July 11, 1974 it is desirable or necessary to dispense into the same test tube or location various diluents or reagents to accompany a sample carried in the microdispenser. Various means have been used to dispense these diluents or reagents including additional hand manipulated microdispensers arranged as pumping means such as is disclosed in co-pending application Ser. No. 662,942 filed Mar. 1, 1976, now abandoned by Thomas E. Lee for "Pipetting Devices". Sometimes the operator needs to dispense the sample first followed by one or more diluents. At other times, discharge of the sample into previously dispensed diluent is the desired procedure.